<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>这是签到题</title>
    <style>
        @keyframes blink {
            0% { opacity: 0; }
            45% { opacity: 0; }
            55% { opacity: 1; }
            90% { opacity: 1; }
            100% { opacity: 0; }
        }
        body {
            background: #000;
            color: #ddd;
            margin: 1em;
        }
        pre:after {
            content: '';
            width: 0.5em;
            height: 1em;
            border-bottom: 2px solid #ddd;
            display: inline-block;
            vertical-align: middle;
            animation: blink 1s infinite;
        }
    </style>
</head>
<body>
    <pre>
/**
 *           DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
 *                    Version 2, December 2004
 *
 * Copyright (C) 2004 Sam Hocevar &lt;sam@hocevar.net>
 *
 * Everyone is permitted to copy and distribute verbatim or modified
 * copies of this license document, and changing it is allowed as long
 * as the name is changed.
 *
 *           DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
 * TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
 *
 *  0. You just DO WHAT THE FUCK YOU WANT TO.
 */
</pre>
<!--
/*                     _ooOoo_
 *                    o8888888o
 *                    88" . "88
 *                    (| -_- |)
 *                    O\  =  /O
 *                 ____/`---'\____
 *               .'  \\|     |//  `.
 *              /  \\|||  :  |||//  \
 *             /  _||||| -:- |||||-  \
 *             |   | \\\  -  /// |   |
 *             | \_|  ''\---/''  |   |
 *     +-------------------------------------+
 *     | nuaactf{buddha_b1ess_us_n0_bug_233} |
 *     +-------------------------------------+
 *       | | :  `- \`.;`\ _ /`;.`/ - ` : | |
 *       \  \ `-.   \_ __\ /__ _/   .-` /  /
 *  ======`-.____`-.___\_____/___.-`____.-'======
 *                     `=---='
 */
-->
<pre>
#include &lt;stdio.h>

int main() {
    printf("Hello friend.");
    printf("Welcome to NUAACTF 2017!");
    printf("Guess where is the flag? It's not that hard.");
}</pre>
</body>
</html>
